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Prescribing for young people with attention deficit hyperactivity disorder in UK primary care: analysis of data from the Clinical Practice Research Datalink

  • Tamsin Newlove-DelgadoEmail author
  • William Hamilton
  • Tamsin J. Ford
  • Ken Stein
  • Obioha C. Ukoumunne
Open Access
Original Article

Abstract

Guidance on management of attention deficit hyperactivity disorder (ADHD) in the UK was issued by the National Institute for Clinical Excellence in 2008. No UK study has examined all psychotropic prescribing in young people with ADHD since the introduction of the guidance; this is especially relevant due to the high prevalence of psychiatric comorbidity in this population. The aim of this study was to describe primary care prescribing of ADHD and other psychotropic medications for young people with ADHD. The analysis of records of patients with an ADHD diagnosis in the UK Clinical Practice Research Datalink from 2005 to 2013 was performed. Estimation of the prevalence of prescribing of ADHD and other psychotropic medications over 8-year follow-up for cases aged 10–20 years in 2005 was carried out. Of 9390 ADHD cases, 61.6% [95% confidence interval (CI) 60.6–62.5%] had a prescription at some point for ADHD medication. Prescribing of other psychotropic medications was higher in girls than in boys (36.4% vs. 22.7%; p < 0.001). ADHD prescribing prevalence declined steeply between the ages of 16 and 18 from 37.8% (95% CI 36.6–38.9) to 23.7% (95% CI 22.7–24.6%). There was a parallel increase in prescribing of other psychotropics from 3.8% (95% CI 3.4–4.3%) to 6.6% (95% CI 6.0–7.3%). There is scope to optimise the management of ADHD and psychiatric comorbidities in young people, and there is a need for sustainable models of ADHD care for young adults, supported by appropriate training and specialist services.

Keywords

Primary health care Prescribing ADHD Comorbidities 

Introduction

Children, young people and adults with attention deficit hyperactivity disorder (ADHD) are at greater risk of experiencing a broad spectrum of poorer outcomes, including higher rates of mortality, injuries and accidents, as well as educational and occupational underachievement (Lichtenstein et al. 2012; Shaw et al. 2012; Dalsgaard et al. 2015; Chang et al. 2014). There are also increased rates of comorbidity with other psychiatric disorders including anxiety, depression and substance misuse, the peak age of emergence for many of these being in late adolescence and early adulthood (Biederman et al. 1991; Copeland et al. 2011; Jensen and Steinhausen 2015; Fayyad et al. 2016). Such coexisting disorders may affect functioning and adherence to medication and furthermore may go undiagnosed and hence untreated (Kooij et al. 2010; Bolea-Alamanac et al. 2014). However, despite the significance of comorbidities in ADHD, prescribing of other psychotropic medications in young people with the condition has been little studied, with most studies focussing on the prescription of ADHD medication only and/or on younger children (Birnbaum et al. 2013; Sikirica et al. 2013).

Moving from adolescence to adulthood, ADHD symptoms can become less overt (for example, manifesting as inner restlessness and disorganisation) and even be mistaken for the signs of other common psychiatric comorbidities (Asherson et al. 2007). Sibley et al.’s (2015) systematic review of persistence suggested that 40–50% of adolescents with ADHD still met criteria for a diagnosis in adulthood where recommended methods such as age-appropriate symptom thresholds were used. However, despite evidence for symptom persistence, internationally, studies of prescribing patterns such as those by Johansen et al. (2015) in the USA and Zetterqvist et al. (2013) in Sweden indicate that there are high rates of treatment discontinuation in late adolescence. Previous UK studies of primary care prescribing have also reported a steep fall in prescribing prevalence of ADHD medication coinciding with the period during which transition from child to adult services takes place (Wong et al. 2009; McCarthy et al. 2012a, b), but these studies used data collected before new guidance was issued by the National Institute for Clinical Excellence (NICE) in 2008. This guidance recommends that young people with ADHD should be reassessed at school-leaving age to determine whether they need to continue treatment into adulthood, and also states that drug treatment is the first-line treatment for adults with moderate or severe levels of impairment resulting from their ADHD. Our recent paper (Newlove-Delgado et al. 2017) used the UK Clinical Practice Research Datalink to examine time to cessation of ADHD medication from age 16, including the most recently available data from 2005 to the end of 2013. However, despite the developments in guidance in treating those reaching adulthood the median time to cessation that we reported was 1.5 years, suggesting a continuing disparity between expected levels of symptom persistence and continuation of medication.

However, no UK study has to date examined all psychotropic prescribing in primary care (both ADHD and non-ADHD medications) in children and young adults with ADHD over this more recent time period, which represents an important gap. In the UK, general practitioners (GPs, primary care doctors) are the ‘gatekeepers’ to specialist services such as child and adolescent psychiatry clinics or paediatric neurodevelopmental clinics. Whilst GPs do not usually undertake diagnosis of ADHD and comorbidities in children and young people, they are often responsible for prescribing regular medication under shared-care arrangements. When young people reach the age boundary for child services at 16–18, there is considerable variation nationally in the services available to them if ongoing treatment is needed (Hall et al. 2015), with some areas of the UK having no available Adult ADHD service to support GPs in prescribing and other aspects of ADHD management. Consequently, knowledge of the more recent patterns both of prescribing of ADHD medication and other psychotropic medications in primary care will allow greater understanding of current practice in managing ADHD and comorbidities in young people. This will contribute to recommendations for commissioning of services, practice and training to improve assessment and wider availability of appropriate management for ADHD and comorbid conditions.

The primary objective of this study was, therefore, to examine the prevalence of primary care prescribing of drugs used to manage ADHD and of other psychotropic medications from 1 January 2005 to 31 December 2013 for people with ADHD aged 10–20 in 2005.

Methods

Study design

This analysis of prescribing uses data from the UK Clinical Practice Research Datalink (CPRD), a large clinical database run by the Medicines and Healthcare products Regulatory Agency (MHRA) which includes prescribing and consultation data from primary care practices across the country (Herrett et al. 2015). We used the CPRD to report the prescribing prevalence of ADHD and other psychotropic medications and the prevalence of recorded psychiatric comorbidities in people with a recorded ADHD diagnosis as defined below. We included cases with ADHD aged from 10 to 20 at any point between 1 January 2005 and 31 December 2005 and analysed the data available on these cases from 1 January 2005 until 31 December 2013. This allowed the study of patterns of primary care prescribing during the period of transition from child to adult services, which usually takes place between the ages of 16 and 18 years.

Inclusion criteria

To be included, firstly, cases needed to be aged 10–20 at some point between 1 January 2005 and 31 December 2005. Secondly, they needed to have a record of an ADHD diagnosis coded in their files at some point between birth and the end of the study period on 31 December 2013. ADHD diagnoses were defined as any of the 22 CPRD medical codes and primary care terms (based on ICD-10 F90 categories) (World Health Organisation 1992) that relate to an ADHD diagnosis (Newlove-Delgado et al. 2017).

Identification of prescriptions and comorbid psychiatric diagnoses

To identify prescriptions of ADHD medication, the files of included cases were searched for prescription records coded with any of the CPRD product codes referring to British National Formulary (BNF) categories of ADHD medication—e.g. stimulants, dated within the study period (Joint National Formulary 2015). Other psychotropic medication prescriptions were identified by searching for records of medications included in BNF Sections 4.1, 4.2 and 4.3 (anxiolytics, antidepressants, mood stabilisers and drugs used in psychoses and related disorders). Antipsychotics and mood stabilisers were grouped together as one category. Comorbid psychiatric diagnoses were identified by searching for codes relating to ICD-10 classifications for the main categories of disorder.

Analysis

Stata SE13 (Statacorp 2015) was used for all data analysis. Prescribing prevalence of ADHD medication was reported, firstly, as the percentage of all cases with a recorded prescription at any point within the study period, and, secondly, by age. For the analysis of prescribing by age, if the case’s registration with a CPRD practice ended before the end of a year then that was counted as an incomplete year and the case was not included. As CPRD does not provide the full date of birth, the age was designated as the age of the case at the end of the calendar year for this analysis.

We also reported the prevalence of prescribing for non-ADHD psychotropic medication and the prevalence of psychiatric comorbidities. We reported prescribing by category of comorbidity. We reported the prevalence of concurrent prescriptions of ADHD and other psychotropic prescriptions occurring in the same calendar year. Finally, to examine secular changes, we reported prevalence of prescribing of ADHD medication by year.

All protocols using patient-level data from the CPRD are reviewed for scientific quality and approved by the Independent Scientific Advisory Committee (ISAC) on behalf of the National Research Ethics Service Committee. This study protocol (13_213) was granted ISAC approval in January 2013.

Results

Sample characteristics

There were 9390 patients with ADHD who met the inclusion criteria. Of these, 7876 (83.9%) were male. The median length of time for which follow-up data were available was 8.7 years (interquartile range 3.2–9.2 years).

Psychiatric comorbidities

Over a quarter of cases (26.0%, 2440/9390) in the sample had another psychiatric diagnosis recorded at some point during follow-up. The most common categories of comorbid psychiatric disorder were autism spectrum disorders (ASD) (9.9%) and anxiety or depressive disorders (9.3%) (Table 1). Psychiatric comorbidity was more prevalent in females than in males (29.4% vs. 25.3%, p = 0.001).
Table 1

Percentage of ADHD cases that had comorbid psychiatric disorders

Disorder category

Percentage of cases with the disorder recorded at any point during follow-up

All cases (N = 9390) (95% confidence interval)

By gender

Males (N = 7876) (%)

Females (N = 1154) (%)

Any comorbid psychiatric disorder

26.0% (25.1–26.9%)

25.3

29.4

Autism spectrum disorder (ASD)

9.9% (9.3–10.5%)

10.3

7.7

Anxiety- or depression-related disorder

9.3% (8.7–9.9%)

8.1

15.9

Conduct/oppositional defiant disorder

5.2% (4.8–5.7%)

5.5

3.8

Substance/alcohol misuse-related disorder

2.1% (1.8–2.4%)

2.0

2.6

Any tic disorder

2.1% (1.8–2.4%)

2.3

1.0

Any personality disorder

1.9% (1.6–2.2%)

1.5

4.0

Bipolar affective disorder or psychosis

0.46% (0.32–0.59%)

0.50

0.26

Prescribing at any point during follow-up

Of all patients, 61.6% (95% CI 60.6–62.5%) had at least one prescription for an ADHD medication during the study period. This percentage was similar between males and females (61.8% vs. 60.4%).

A quarter of all cases (24.9%; 95% CI 24.0–25.8%) had at least one prescription for another psychotropic medication at some point during the study period, with the most commonly prescribed category being antidepressants (Table 2). Females had a higher prevalence of being prescribed a non-ADHD psychotropic medication (36.4% vs 22.7%, p < 0.001), in particular of being prescribed antidepressants and anxiolytics.
Table 2

Percentage of ADHD cases that were prescribed non-ADHD psychotropic medication by gender and age

Medication category (British National Formulary 2015)

Percentage with at least one prescription at any point during follow-up

All cases (N = 9390) (95% confidence interval)

By gender

Males (N = 7876) (%)

Females (N = 1154) (%)

Any non-ADHD psychotropic medication

24.9% (24.0–25.8%)

22.7

36.4

Antidepressants

16.0% (15.3–16.8%)

13.6

28.7

Anxiolytics

5.8% (5.3–6.2%)

5.1

9.2

Antipsychotics and mood stabilisers

10.7% (10.1–11.3%)

10.5

11.4

Of those with a recorded comorbidity, 49.2% (95% CI 47.1–51.1%) had a prescription for a non-ADHD psychotropic medication at any point versus 16.8% (95% CI 16.0–17.7%) of those without recorded comorbidity. In those with a comorbid disorder, prescribing of non-ADHD psychotropic medication was higher amongst females than in males (64.4% vs. 45.7%; p < 0.001).

There were clear differences between diagnostic groups on examining non-ADHD psychotropic prescribing (Table 3). Antipsychotic and mood stabiliser prescribing was highest amongst those with a recorded tic disorder (42.4% had a prescription at some point). Unsurprisingly, participants with a recorded diagnosis of anxiety or depression were more likely than other groups to be prescribed antidepressants.
Table 3

Percentage of ADHD cases that were prescribed psychotropic medication by type of recorded psychiatric comorbidity

Type of recorded psychiatric comorbidity

Percentage prescribed a drug from British National Formulary category of medication at any point during the study period (95% confidence interval)

ADHD medication

Antidepressants

Antipsychotics or mood stabilisers

No recorded comorbidity (N = 7055)

61.0% (60.0–62.2%)

10.3% (9.6––11.0%)

6.4% (5.9–7.0%)

Any recorded comorbidity (N = 2335)

63.1% (61.1–65.0%)

33.4% (31.5–35.3%)

23.6% (21.9–25.4%)

Autism spectrum disorder (N = 927)

67.7% (64.7–70.7%)

19.3% (16.9–22.0%)

25.1% (22.4–28.0%)

Conduct/oppositional defiant disorders (N = 490)

63.7% (59.3–67.8%)

17.6% (14.4–21.2%)

18.2% (15.0–21.8%)

Depression- or anxiety-related disorders (N = 876)

58.8% (55.5–62.0%)

60.8% (57.6–64.0%)

22.2% (16.9–28.6%)

Tic disorders (N = 198)

63.6% (56.7–70.1%)

22.2% (16.9–28.6%)

42.4% (35.7–49.5%)

Concurrent prescribing of ADHD and psychotropic medications

Just under 1 in 10 cases (8.8%, 95% CI 8.3–9.4%) had a prescription for both an ADHD medication and a non-ADHD psychotropic medication within the same calendar year. This percentage was higher amongst females (11.1% vs. 8.4% in males).

Prescribing by age

Prescribing by age is summarised in Fig. 1. Over the transition period from child to adult services there was evidence of rapidly falling prevalence. Amongst 16-year-olds, prevalence of prescribing of ADHD medication was 37.8% (95% CI 36.6–38.9%) falling to 23.7% (95% CI 22.7–24.6%) in 18-year-olds. In contrast, for other psychotropic prescriptions, from the age of 16 onwards there was a clear rise so that at the age of 18, 6.6% (95% CI 6.0–7.3%) had a prescription.
Fig. 1

Percentage of ADHD cases that were prescribed ADHD medication and other psychotropic medications by age. Bars indicate 95% confidence interval

As Fig. 2 demonstrates, patterns of ADHD medication prescribing by age followed a similar pattern in each year of the study period, with the sharpest drop in prescribing consistently seen between the ages of 16 and 18 years.
Fig. 2

Percentage of ADHD cases that were prescribed ADHD medication by age and study year

Discussion

Summary

Our results clearly demonstrate a marked decline in the prevalence of ADHD prescribing over the period in which transition from child to adult services takes place in the UK and a parallel rise in the prevalence of other psychotropic prescribing. A quarter of all cases had a prescription at some point for non-ADHD psychotropic medication. We found that girls with ADHD were more likely to have a recorded diagnosis of comorbid depression or anxiety alongside ADHD and to be prescribed non-ADHD psychotropic medication.

Strengths and limitations

The chief strength of this analysis was the use of high-quality and recent data from a national database capturing current practice in primary care prescribing until the end of 2013, covering a period following the introduction of the UK NICE ADHD guidance.

In the UK, primary care databases are likely to provide the fullest picture of prescribing due to widespread shared-care protocols for ADHD (Ford et al. 2008). However, they fail to capture the smaller proportion of prescribing taking place in specialist services which might include shorter-term trials. Prescribing for those who de-registered from their practice would also no longer be captured in CPRD if they did not re-register with a CPRD-affiliated practice. These cases might represent a slightly different population, for example, those moving away for education. Although estimates of validity of diagnoses in the CPRD are generally high, particularly for non-acute conditions, relying on clinician-coded diagnoses of ADHD to select cases might introduce bias (Herrett et al. 2010).

Perhaps the most significant limitation of this study when considering the implications regarding under-treatment or the appropriateness of treatment is that the data set did not contain information on several important factors that may influence prescribing. Data were not available on the severity of ADHD and of comorbid conditions, or on the specific indication for medication.

Comparison with existing literature

The decline in prescribing of ADHD medication in late adolescence that we describe coincides with the period of transition from child to adult services. The decline appears steeper and in excess of what would be expected from follow-up studies of persistence of symptoms (Faraone et al. 2006; Sibley et al. 2015). When examining secular trends, this pattern was still evident in the most recent years (2012 and 2013) included in this study. In contrast, Johansen et al.’s (2015) US study of ADHD prescribing found a much more gradual drop in the use of medication between the ages of 12 and 23 years, which supports the suggestion that prescribing will be heavily influenced by external factors such as service availability and attitudes of prescribers and patients (Hall et al. 2015; Matheson et al. 2013).

The proportion of adults with ADHD who are prescribed drugs for ADHD appears to have risen over time, albeit from a very low base. In 2008, NICE estimated that 1.2% of UK adults with ADHD were currently receiving ADHD medication, compared to our finding that 14–15% of adults over 20 had a prescription. This rise has been reported in previous studies covering earlier and overlapping time periods in the UK, as well as worldwide by Johansen et al. (2015), Zetterqvist et al. (2013), McCarthy et al. (2012a, b) and Raman et al. (2018). Therefore, this study, which uses prescribing records from between 2005 and 2013, may underestimate current 2018 rates of prescribing due to rapid changes in practice and service development. However, very recent reports highlight concern that some UK Adult ADHD services may be in the process of being decommissioned, and others have expanding waits, both factors which could act to influence prescribing prevalence and practice (Iacobucci 2018).

The rise in the prevalence of non-ADHD psychotropic prescribing in late adolescence is not unexpected, given that this is the peak age for emergence of new mental health diagnoses, whilst ADHD symptoms decline with age (Copeland et al. 2011). It is, however, plausible that these prescribing trends might represent prescribing of antidepressant or other psychotropic medications at the expense of treating ADHD, as symptoms of ADHD in adults may be less well recognised or mistaken for those of other psychiatric disorders (Kooij et al. 2010; Asherson et al. 2007).

Comorbidity is considered to be the rule rather than the exception in children and adults with ADHD (Jensen and Steinhausen 2015; Fayyad et al. 2016), and yet in this study only a quarter of all cases had a recorded comorbid psychiatric diagnosis during the study period. Of particular note was the very low prevalence of recorded substance or alcohol use disorders. Estimates from comorbidity studies are usually based on screening clinical samples using diagnostic instruments that will actively detect difficulties, and in our study diagnoses were recorded in routine practice. It is not possible to determine whether comorbid disorders were detected but not recorded. It is feasible, however, to suggest that the low prevalence we report could reflect under-diagnosis of certain common comorbid conditions.

Almost a fifth of cases with a comorbidity had a concomitant prescription of ADHD and other psychotropic medications, which is similar to the findings of Sikirica et al.’s (2013) European study. The overall prevalence of antipsychotic and mood stabiliser prescribing in our sample was 10%, which is in line with the results of a US study by Birnbaum et al. (2013) estimating that approximately 11% of young people with ADHD were also prescribed antipsychotics. A quarter of those with recorded comorbid ASD had antipsychotic or mood stabiliser prescriptions. Similarly, worldwide psychopharmacology studies suggest that antipsychotics are the most commonly prescribed class of drug in adults and children with ASD (Hsia et al. 2014; Jobski et al. 2016; Piñeiro-Dieguez et al. 2016), with a recent US study reporting that 20% of insured children with ASD were prescribed antipsychotics and 9% mood stabilisers (Madden et al. 2017).

Finally, our findings imply that females are more likely to be pharmacologically treated in primary care for psychiatric comorbidities with ADHD than males. The literature does suggest that there are gender differences in the identification and management of ADHD. Girls may face higher barriers to referral and to receiving a diagnosis (Maniadaki et al. 2006; Groenewald et al. 2009; Ohan and Visser 2009). Given that the females in our sample had been clinically recognised and referred, they may have represented a more severely affected group than males.

Implications for research and practice

Whilst this was a UK-based study, there are aspects which are generalizable internationally. For example, the challenges of transition and the fall in prescribing in ADHD medication over this period are described across international health systems (Johansen et al. 2015; Broad et al. 2017). Primary care physicians in many developed countries including the USA also have an important role in the management of ADHD in this group, meaning that the messages from this research will be relevant to international primary care practice and research (Bolea-Alamanac et al. 2014; Patel et al. 2017). The findings on the decline in ADHD prescribing, the gender differences in other psychotropic prescribing and the recorded prevalence of comorbid disorders all suggest that there is scope to optimise the management of ADHD over the transition period and improve the identification and treatment of psychiatric comorbidities amongst adolescents and adults.

Recent studies by Hall et al. (2015) have reported on inadequate provision of specialist services for this group in the UK. Furthermore, UK GPs perceive a range of barriers in managing adolescent mental health problems, including time and lack of training (O’Brien et al. 2016), and also report problems in gaining access to such specialist services for their patients (Roberts et al. 2013). Current UK guidance recommends that ADHD medication requires occasional review by a specialist, and where such services are not available this will limit the GP’s ability to prescribe (NICE 2018). Ongoing efforts are therefore required to support and encourage holistic treatment where it may be helpful to the young adult with ADHD. Sustainable models are needed to provide age-appropriate services to advise and liaise with primary care and support shared-care protocols (Coghill 2015; Young et al. 2016). There is a strong case for further training for GPs and specialists not only on ADHD but on psychiatric comorbidities in the context of ADHD in both genders.

In terms of future research, in order to invest in improving ADHD management, the various models of delivering services need to be evaluated in terms of outcomes, cost-effectiveness and acceptability. A better understanding of the perspectives of service users themselves might also increase engagement with pharmacological and non-pharmacological interventions. Similarly, relatively little is known about what might influence the specific ADHD prescribing practices of clinicians in primary care. Further research into their perspectives and diagnostic and treatment practices is likely to help identify and address barriers to improved management.

Notes

Funding

This research was funded as part of a Doctoral Research Fellowship from the National Institute for Health Research held by Tamsin Newlove-Delgado (Reference: DRF-2012-05-221). Tamsin Newlove-Delgado is currently funded by an NIHR Academic Clinical Lectureship. Ken Stein and Obioha C. Ukoumunne are funded by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC) for the South West Peninsula at Royal Devon and Exeter NHS Foundation Trust. This report is independent research, and the views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health.

Compliance with ethical standards

Conflict of interest

The authors declare no competing interests.

Ethical approval

All protocols using patient-level data from the CPRD are reviewed for scientific quality and approved by the Independent Scientific Advisory Committee (ISAC) on behalf of the National Research Ethics Service Committee. This study protocol (13_213) was granted ISAC approval in January 2013.

References

  1. Asherson P, Chen W, Craddock B, Taylor E (2007) Adult attention-deficit hyperactivity disorder: recognition and treatment in general adult psychiatry. Br J Psychiatry 190(1):4–5CrossRefGoogle Scholar
  2. Biederman J, Newcorn J, Sprich S (1991) Comorbidity of attention deficit hyperactivity disorder with conduct, depressive, anxiety and other disorders. Am J Psychiatry 148:564–577CrossRefGoogle Scholar
  3. Birnbaum ML, Saito E, Gerhard T et al (2013) Pharmacoepidemiology of antipsychotic use in youth with ADHD: trends and clinical implications. Curr Psychiatry Reports 15(8):382.  https://doi.org/10.1007/s11920-013-0382-3 CrossRefGoogle Scholar
  4. Bolea-Alamanac B, Nutt DJ, Adamou M et al (2014) Evidence-based guidelines for the pharmacological management of attention deficit hyperactivity disorder: update on recommendations from the British Association for Psychopharmacology. J Psychopharmacol 28:179–203CrossRefGoogle Scholar
  5. Broad KL, Sandhu VK, Sunderji N, Charach A (2017) Youth experiences of transition from child mental health services to adult mental health services: a qualitative thematic synthesis. BMC Psychiatry 17(1):380CrossRefGoogle Scholar
  6. Chang Z, Lichtenstein P, D’Onofrio BM et al (2014) Serious transport accidents in adults with attention-deficit/hyperactivity disorder and the effect of medication: a population-based study. JAMA Psychiatry 71(3):319–325CrossRefGoogle Scholar
  7. Coghill D (2015) Services for adults with ADHD: work in progress: Commentary on Specialist adult ADHD clinics in East Anglia. BJPsych Bull 39:40–43.  https://doi.org/10.1192/pb.bp.114.048850 CrossRefGoogle Scholar
  8. Copeland W, Shanahan L, Costello EJ, Angold A (2011) Cumulative prevalence of psychiatric disorders by young adulthood: a prospective cohort analysis from the Great Smoky Mountain Study. J Am Acad Child Adolesc Psychiatry 50(3):252–261.  https://doi.org/10.1016/j.jaac.2010.12.014 CrossRefGoogle Scholar
  9. Dalsgaard S, Ostergaard SD, Leckman JF et al (2015) Mortality in children, adolescents, and adults with attention deficit hyperactivity disorder: a nationwide cohort study. Lancet 385(9983):2190–2196CrossRefGoogle Scholar
  10. Faraone SV, Biederman J, Mick E (2006) The age-dependent decline of attention deficit hyperactivity disorder: a meta-analysis of follow-up studies. Psychol Med 36:159–165CrossRefGoogle Scholar
  11. Fayyad J, Sampson NA, Hwang I et al (2016) The descriptive epidemiology of DSM-IV Adult ADHD in the World Health Organization World Mental Health Surveys. Atten Defic Hyperact Disord 1:47–65Google Scholar
  12. Ford T, Fowler T, Langley K et al (2008) Five years on: public sector service use related to mental health in young people with ADHD or hyperkinetic disorder five years after diagnosis. Child Adolesc Mental Health 13(3):122–129CrossRefGoogle Scholar
  13. Groenewald C, Emond A, Sayal K (2009) Recognition and referral of girls with Attention Deficit Hyperactivity Disorder: case vignette study. Child Care Health Dev 35(6):767–772CrossRefGoogle Scholar
  14. Hall CL, Newell K, Taylor J et al (2015) Services for young people with attention deficit/hyperactivity disorder transitioning from child to adult mental health services: a national survey of mental health trusts in England. J Psychopharmacol 29:39–42CrossRefGoogle Scholar
  15. Herrett E, Thomas SL, Schoonen WM et al (2010) Validation and validity of diagnoses in the General Practice Research Database: a systematic review. Br J Clin Pharmacol 69(1):4–14CrossRefGoogle Scholar
  16. Herrett E, Gallagher AM, Bhaskaran K et al (2015) Data resource profile: Clinical Practice Research Datalink [CPRD]. Int J Epidemiol 44:827–836CrossRefGoogle Scholar
  17. Hsia Y, Wong AYS, Murphy DGM et al (2014) Psychopharmacological prescriptions for people with autism spectrum disorder [ASD]: a multinational study. Psychopharmacology 231(6):999–1009CrossRefGoogle Scholar
  18. Iacobucci G (2018) Adult ADHD prescribing left to GPs. BMJ 358:4444Google Scholar
  19. Jensen C, Steinhausen HC (2015) Comorbid mental disorders in children and adolescents with attention-deficit/hyperactivity disorder in a large nationwide study. Attent Defic Hyperact Disord 7(1):27–38CrossRefGoogle Scholar
  20. Jobski K, Höfer J, Hoffmann F, Bachmann C (2016) Use of psychotropic drugs in patients with autism spectrum disorders: a systematic review. Acta Psychiatr Scand.  https://doi.org/10.1111/acps.12644 Google Scholar
  21. Johansen ME, Matic K, McAlearney AS (2015) Attention deficit hyperactivity disorder medication use among teens and young adults. J Adolesc Health 57:192–197CrossRefGoogle Scholar
  22. Joint Formulary Committee (2015) British National Formulary, 60th edn. BMJ Group and Pharmaceutical Press, LondonGoogle Scholar
  23. Kooij SJJ, Bejerot S, Blackwell A et al (2010) European consensus statement on diagnosis and treatment of adult ADHD: the European Network Adult ADHD. BMC Psychiatry 3(10):6Google Scholar
  24. Lichtenstein P, Halldner L, Zetterqvist J et al (2012) Medication for attention deficit-hyperactivity disorder and criminality. NEJM 367(21):2006–2014CrossRefGoogle Scholar
  25. Madden JM, Lakoma MD, Lynch FL et al (2017) Psychotropic medication use among insured children with autism spectrum disorder. J Autism Dev Disord 47(1):144–154CrossRefGoogle Scholar
  26. Maniadaki K, Sonuga-Barke E, Kakouros E (2006) Adults’ self-efficacy beliefs and referral attitudes for boys and girls with AD/HD. Eur Child Adolesc Psychiatry 15(3):132–140CrossRefGoogle Scholar
  27. Matheson L, Asherson P, Wong ICK et al (2013) Adult ADHD patient experiences of impairment, service provision and clinical management in England: a qualitative study. BMC Health Serv Res 13:184CrossRefGoogle Scholar
  28. McCarthy S, Wilton L, Murray ML et al (2012a) The epidemiology of pharmacologically treated attention deficit hyperactivity disorder [ADHD] in children, adolescents and adults in UK primary care. BMC Pediatr 12:78CrossRefGoogle Scholar
  29. McCarthy S, Wilton L, Murray ML et al (2012b) Persistence of pharmacological treatment into adulthood, in UK primary care, for ADHD patients who started treatment in childhood or adolescence. BMC Psychiatry 12:219CrossRefGoogle Scholar
  30. Newlove-Delgado TV, Ford TJ, Ukoumunne OC, Hamilton W, Stein K (2017) Prescribing of medication for attention deficit hyperactivity disorder among young people in the Clinical Practice Research Datalink 2005–2013: analysis of time to cessation. Eur Child Adolesc Psychiatry.  https://doi.org/10.1007/s00787-017-1011-1 Google Scholar
  31. NICE (2008) CG72 attention deficit hyperactivity disorder [ADHD]: NICE guideline. NICE, LondonGoogle Scholar
  32. NICE (2018) Attention deficit hyperactivity disorder: diagnosis and management. NICE Guideline 87. NICE, LondonGoogle Scholar
  33. O’Brien D, Harvey K, Howse J, Reardon T, Creswell C (2016) Barriers to managing child and adolescent mental health problems: a systematic review of primary care practitioners’ perceptions. Br J Gen Pract 66(651):e693–e707.  https://doi.org/10.3399/bjgp16X687061 CrossRefGoogle Scholar
  34. Ohan JL, Visser TAW (2009) Why is there a gender gap in children presenting for Attention Deficit/Hyperactivity Disorder services? J Clin Child Adolesc Psychiatry 38(5):650–660CrossRefGoogle Scholar
  35. Patel A, Medhekar R, Ochoa-Perez M et al (2017) Care provision and prescribing practices of physicians treating children and adolescents with ADHD. Psychol Serv 68(7):681–688CrossRefGoogle Scholar
  36. Piñeiro-Dieguez B, Balanzá-Martínez V, García-García P, Soler-López B (2016) Psychiatric comorbidity at the time of diagnosis in adults with ADHD. J Attent Disord 20(12):1066–1075CrossRefGoogle Scholar
  37. Raman SR, Man KKC, Bahmanyar S et al (2018) Trends in attention-deficit hyperactivity disorder medication use: a retrospective observational study using population-based databases. Lancet Psychiatry 5:824–835CrossRefGoogle Scholar
  38. Roberts JH, Crosland A, Fulton J (2013) “I think this is maybe our Achilles heel…” exploring GPs’ responses to young people presenting with emotional distress in general practice: a qualitative study. BMJ Open 3(9):e002927CrossRefGoogle Scholar
  39. Shaw M, Hodgkins P, Caci H et al (2012) A systematic review and analysis of long-term outcomes in attention deficit hyperactivity disorder: effects of treatment and non-treatment. BMC Med 10:99CrossRefGoogle Scholar
  40. Sibley MH, Mitchell JT, Becker SP (2015) Method of adult diagnosis influences estimated persistence of childhood ADHD: a systematic review of longitudinal studies. Lancet Psychiatry 3:1157–1165.  https://doi.org/10.1016/S2215-0366%5b16%5d30190-0 CrossRefGoogle Scholar
  41. Sikirica V, Fridman M, Bruno A et al (2013) Concomitant pharmacotherapy of psychotropic medications in EU children and adolescents with attention-deficit/hyperactivity disorder. Drugs R&D 13(4):271–280.  https://doi.org/10.1007/s40268-013-0034-4 CrossRefGoogle Scholar
  42. StataCorp (2015) Stata statistical software: release 14. StataCorp LP, College StationGoogle Scholar
  43. Wong ICK, Asherson P, Bilbow A et al (2009) Cessation of attention deficit hyperactivity disorder drugs in the young [CADDY]—a pharmacoepidemiological and qualitative study. Health Technol Assess 13:1–120Google Scholar
  44. World Health Organisation (1992) International statistical classification of diseases and related health problems, 10th revision [ICD-10]. World Health Organisation, GenevaGoogle Scholar
  45. Young S, Adamou M, Asherson P et al (2016) Recommendations for the transition of patients with ADHD from child to adult healthcare services: a consensus statement from the UK Adult ADHD Network. BMC Psychiatry 16:301.  https://doi.org/10.1186/s12888-016-1013-4 CrossRefGoogle Scholar
  46. Zetterqvist J, Asherson P, Halldner L et al (2013) Stimulant and non-stimulant attention deficit/hyperactivity disorder drug use: total population study of trends and discontinuation patterns 2006–2009. Acta Psychiatr Scand 128:70–77CrossRefGoogle Scholar

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Authors and Affiliations

  1. 1.University of Exeter Medical SchoolExeterUK
  2. 2.NIHR CLAHRC South West Peninsula [PenCLAHRC]University of Exeter Medical SchoolExeterUK

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